[A single centre study about the effects of HFR on anemia]

Erythropoietin (EPO) deficiency, erythropoiesis inhibition and reduction in red blood cell survival are the main causes of anemia in endstage renal disease (ESRD). Hemodiafiltration (HDF) with on-line endogenous reinfusion eliminates backfiltration and uses an ultrapure dialysate and reinfusate. This technique should improve anemia correction by increasing uremic toxin removal and reducing inflammatory cytokine production. In this study, we evaluated the effects of HDF with on-line endogenous reinfusion on anemia correction.

This was a single-center, prospective and non-randomized study. We selected 12 patients on EPO therapy with steady haemoglobin (Hb) values; eight patients were treated with bicarbonate dialysis and four patients with on-line HDF. We switched them to HDF with on-line endogenous reinfusion for 6 months, changing the EPO dose when Hb levels were not within the 11-12 g/dL range. Biochemical data were measured every month. Results are expressed as means +/- m.s.e. Data were analyzed using the Student's t-test and analysis of variance for repeated measurements. A value p<0.05 was considered statistically significant.

Patients maintained the same Hb, ferritin and dialytic efficiency throughout the study. The EPO supplementation was significantly higher in patients treated with bicarbonate dialysis (108 +/- 8 UI/kg/week as compared with patients treated with on-line HDF (36 +/- 5 UI/kg/week) during the 6 months before treatment by HDF with on-line endogenous reinfusion. In the last 6 months, we detected a reduction in EPO consumption, but not statistically significant, in the patients switched from bicarbonate dialysis to HDF with on-line endogenous reinfusion (83 +/- 6 UI/kg/week).

The change from bicarbonate dialysis to HDF with on-line endogenous reinfusion caused a reduction in EPO supplementation and, consequently, a reduction in the cost of anemia therapy. It is necessary to increase the size of the study group and to prolong the observation period to possibly obtain statistical significances.